There is a lot higher emissions standards now for diesel now in the U.S. now. Look at the vw jetta tdi a 2005 gets better mpg's than a 2012 U.S. car companies don't think they're worth building. People still think diesels are loud, smoke and slow. The is not the case anymore. If vw diesels were to out sell the prius they would be trying to make a diesel car.

now

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"It's all good. We've caught a lot nicer shit than this on fire"

1: Emissions, a brand new truck that gets 10mpg pollutes exponentially less then an 86 whatever that gets 35mpg.

2: See above (Nuggets Post), 50mpg in Europe = 41.635mpg in the USA. It's amazing how many people don't realize that.

3: It is possible to make a cheap 40mpg shitbox that nobody wants to drive. It's called the FIAT 500. If you've never driven a car in Europe, they're small, slow, and just not suited for the American market. It's been tried, and has failed every time.

I'm all for efficiency over clean, but that's just not the way the world works.

To immediately address the question of the Taurus vs. the VW and gasoline polluting more per mile driven.

Right now, that is not the case, as that Taurus meets SULEV standards and the VW is only required to meet ULEV numbers. So, while the Ford burns 2.5x the amount of fuel, the VW emits:

5.5x the amount of NMOG (non-methane organic gasses)
2.1x the amount of CO
3.5x the amount of NOx

I agree with your reasoning though - and applaud the thought - but your example ends up being a numbers game for emission standards. Soon, diesels will need to be SULEV emission capable, and you will see a corresponding drop in fuel economy. It will still be higher than most gasoline powered cars, but the gap will decrease enough that you might think twice about buying a diesel.

BTW:
Diesel fuel in the U.S. is the same low sulphur content as in Europe, our cetane is a bit lower - but ULSD is now the only legal diesel fuel for use in licensed motor vehicles.

Why fuel economy sucks these days:

1. You, the consumer:

A. Performance.

The tempo mentioned before:

52 Horsepower. The 90-hp 2.3L gas engined car went from 0-60 in a blistering 13.0 seconds. I can't find data on the diesel, but if it is like my old Jetta diesel, it was probably close to 16 seconds.
Cars today - even econoboxes - get shit upon if they don't reach 60 mph in under 10 seconds. Higher power is needed for that, so fuel economy goes down.

B. Safety.

Tempo: curb weight of roughly 2500 lb.
Chad's Fuckus: 3000 lb.

Just under 250 kg of extra mass that needs to be accelerated and decelerated. The Fukus is also capable of 8.0 seconds 0-60 and has heavier brakes to slow the additional mass - and in much a shorter stopping distance than the Tempo.

Everyone wants a 5-star crash rating, the government has imposed airbags to protect the stupid, . Fact is, we all want to have the best chance of walking away from an accident or want to protect our family the best we can. All of that adds mass. More energy is required to get the extra shit moving.

C. Amenities.

Try to find a vehicle w/o air conditioning, power door locks, power steering, power buttplug, etc - it's hard. I'd imagine less than 10% of the market is equipped with manual windows / door locks / whatever.
Luxury items from 20 years ago are standard on today's cars.
Sound deadening, 20-speaker infotainment systems, et al all add mass to the vehicle AND increase the parasitic loads on the engine by increasing the electrical demand on the alternator, adding a power steering pump and an A/C compressor.

My old man had one of the first Tempos with a 2.3L M/T no air, no power and an am muthafuckin radio and was able to get 42 MPG highway in that thing.

Oh, I almost forgot - That Tempo was sold when the national speed limit was 55mph and now you assholes demand 40mpg driving 75mph. Wind resistance has that fukin' exponent on the velocity term, i.e. it takes over twice the amount of energy to push a car through the air at 80 mph than it does 55 mph.

2. The government & its silly little regulations.

Emissions standards and all the "trouble" they create are actually quite a good thing. Emission control systems operate near 100% efficiency - and are not too restrictive (gasoline systems). Their drawback is added cost for more componentry and the significant contribution to the vehicle's weight.

Diesel particulate filters are a bit restrictive, but the overall downside of those (including added mass of the aftertreatment system) is that you use "non-torque producing" fuel to burn off / clean the filter at regular intervals.

The reason why having emission standards is a good think is once you scale up pollutants coming from a manufacturer's fleet. That's a huge number of vehicles and the output has to be low, as we're trying to offset all the old vehicles operating with old, broken or deleted systems - AND trying to make the systems we equip today last 150,000 miles. (Yep - that increases your vehicle's price too)

In closing:

Passive safety and 4,6,10,20-airbag systems that come with 5-star crash ratings, emission systems and all the "features" the customer "has to have" in a vehicle increases mass. Mass goes up, fuel economy goes down.
Customers will not settle for a 15-second 0-60 automobile, so bigger/more "featured" powertrains also increase mass.

It is hard to believe, but the vehicle mass has the most impact on today's fuel economy numbers. There is no conspiracy. Seriously, WTF!? First people say the Volt was the government forcing GM to build a fuel-efficient car, and now shit's swung full opposite scale.

So, you want to go fast, be safe and have all the luxuries of a Cadillac AND get 50 mpg?

No, I pooped before I typed it because I knew my legs would fall asleep if I replied while on the toilet.

What are your thoughts about what kickstand mentioned on the refining process? Do refineries have the same standards for polluting? If we focused more on mpg's would the reduction of pollutants in the refining process outweigh the increase in vehicle pollutants?

3: It is possible to make a cheap 40mpg shitbox that nobody wants to drive. It's called the FIAT 500. If you've never driven a car in Europe, they're small, slow, and just not suited for the American market. It's been tried, and has failed every time.

To put this out there, the little Fiat 500 doesn't get 40mpg. Rated at 32 or 34 with an auto on the highway, and 38 with a manual. Ford/GM have better econobox ratings (Cruze, Focus) and they're double the car.

Some more information as I dive through this stuff today (wow, work related even), US NOx limits (tier 2 bin 5) are significantly lower than Euro V/VI, while we allow a higher CO limit than their regs.

Scooter (or how ever it is capitalized) Thanks for providing a solid well informed/scientific answer to my statement/question. I knew that it was a logic, with limited knowledge, based statement and you answered just how I was hoping you would. My thoughts and opinions on this issue are over.

So the weight is more of a problem for fuel economy than the emissions regulations? Throws my comment right out the window.

Yet, they're a function of each other - so you're not totally out of the scope of the problem. How much do you think this exhaust weighs?

vs.

Not only do you have the SCR for NOx, it needs a tank and injection system for urea, the DOC, DPF, additional injection system for regen, many extra sensors AND some of that exhaust pipe is double wall for retaining heat.

Everything plays a part - I just want the misconception out there that the emissions system increases backpressure so much that it cost you 5 mpg.

Scooter (or how ever it is capitalized) Thanks for providing a solid well informed/scientific answer to my statement/question. I knew that it was a logic, with limited knowledge, based statement and you answered just how I was hoping you would. My thoughts and opinions on this issue are over.

Any time.

I've been doing engine / emission calibration for about 20 years and now work in the advanced area where fuel economy improvements are the highest priority (while meeting future emission regulations, of course )

What are your thoughts about what kickstand mentioned on the refining process? Do refineries have the same standards for polluting? If we focused more on mpg's would the reduction of pollutants in the refining process outweigh the increase in vehicle pollutants?

I don't know much about refining, other than we're overcapacity on the outdated refineries we have. I'd imagine it's like comparing coal-fired power plants to natural gas ones - thereabouts.

To immediately address the question of the Taurus vs. the VW and gasoline polluting more per mile driven.

Right now, that is not the case, as that Taurus meets SULEV standards and the VW is only required to meet ULEV numbers. So, while the Ford burns 2.5x the amount of fuel, the VW emits:

5.5x the amount of NMOG (non-methane organic gasses)
2.1x the amount of CO
3.5x the amount of NOx

I agree with your reasoning though - and applaud the thought - but your example ends up being a numbers game for emission standards. Soon, diesels will need to be SULEV emission capable, and you will see a corresponding drop in fuel economy. It will still be higher than most gasoline powered cars, but the gap will decrease enough that you might think twice about buying a diesel.

I lied when I said my thoughts and comments were over.

Now if I am reading what you posted correctly there will be a tipping point where the pollutant level of the VW will be equal or less than that of a Taurus. That point will only come when the fuel savings of a VW will be 5.5x greater than the Taurus.

From my SWAG numbers of MPG earlier and some calculations just now at no point will the VW pollute less since the difference in MPG is less than of 5.5X what the Taurus gets for MPG. I used 5.5 since that was what the highest difference between the two emission standards you posted. The only way for the VW to achieve that tipping point would be if the MPG was at least 110MPG. Correct in my thinking or no.

I am curious, how many more miles per gallon could we get out of our cars if we lightened the restrictions on emissions of the auto manufacturers by x%, Now after doing that, how many less gallons of fuel would we use as a nation, and now, how many emissions have been eliminated from the refinery process, and how many less barrels are we using?

Are you saying if we used less fuel overall we would not need to make as many shipments of oil from the Middle East to America on ships that burn fuel and pollute. Then once it is here we would not need as many trucks delivering the refined oil to the gas stations burning fuel and polluting? Are you trying to imply that a point could be reached within reason as to the amount of pollution released by the delivery of the gas would be less than the pollution released by the general public in commuting if we focused on MPG improvements rather than tighter emission standards?